Electric soldering-iron



(No Model.)

C. L. GOFPIN. ELECTRIC SOLDERING IRON.

Patented July l, 1890.

me News versus co., PHonrumo., msnmcruw, u. c,

UNITED STATES PATENT OEErcE.

VACHARLES L. COFFIN, OF DETROIT, MICHIGAN.

ELECTRIC'SOLDERING-IRON.

SPECIFICATION forming part Vof Letters Patent No. 431,439, dated July 1, 1890.

Application led January 18, 1890. Serial No. 337,299. (No model.) Y

To all whom t may concern.-

Be it known that I, CHARLES L. COEEIN, of Detroit, in the county of Wayne and State of Michigan, have invented a new andy useful Improvement in Electrically-Heated Soldering-Irons, of which the following is a speciiication.

My invention consists in an electricallyheated soldering-iron hereinafter fully described and claimed.

Figures l, 2, 3, and 4 are longitudinal central sections, the shank and handle being broken away in Fig. 4. Fig. 5 is a top plan view of a portion of the shank and iron. Fig. 6 is a section on line Fig. 3. Fig. 7 is a section on line y y, Fig. 4. Fig. 8 is a diagram showing the operation of the tool. Fig. 9 is a section on line z a, Fig. 5.

In all the figures, A represents the soldering iron orhead proper, which is usually made of copper and pointed at its end.

B represents the shank of the soldering-iron secured thereto in any convenient way, and C represents an ordinary wooden handle.

In Fig. 1, D and E represent conductors which extend through the shank, being insulated from each other and provided with bindn ing-screws at the end of the handle C for the attachment of .the electric circuit.

G represents a spiral conductor contained within the soldering-iron A, (insulated therefrom,) which extends from the conductor D down nearly to the end of the head A and returns to the conductorE. A convenient way in which to make this conductor G is to make it in spirals of two different diameters, as shown in the drawings, whereby one leg of the conductor returns within the other leg. In whatever form this conductor G be made it is intended to be a conductor of higher resistance than conductors D and E, so that it will become heated by the passage of an electric current. The conductorF. is shown broken at the point I., and K represents a lever pivoted at m to the handle, provided with a spring n and carrying a block 7c, which, when pressed into contact with the conductor E, completes the said conductor by bridging the break.

I represents insulating material in all the figures.

In Fig. 2 the arrangement differs from that of Fig. 1 only in that the conductor G is connected with the head A of the soldering-iron at the point thereof, the return being through the soldering-iron and the shank B, the iron into bits which will pass through the opening, f

or by being pushed into said opening in the form of a wire. In this form F represents the inner wall of head A, and Q represents adiaphragm which shuts od the soldering-head from the shank. IIA represents a rod which passes through the head of the soldering-iron and through the diaphragm Q, and is provided at its end with a plug H, adapted to close an aperture O in the point of the head. h represents a shoulder on rod I-l, between which and a shoulder in the shank is a coil-spring n, tending to normally press the plug Il against the aperture in the end of the head. N represents a thumb-piece on the end of rod II', passing out through a slot in handle C, by which the plug II can be retracted to permit molten solder to flow through aperture O.

The arrangement of Fig. 1l differs from that of Fig. 3 only in that the conductor D is con nected directly with the outer spiral conductor G, and the return to conductorE is made by an inner spiral, as in Fig. l. This throws the reservoir to one side ot' the center, and the rod H is therefore curved near its end to brin g the plug` H in the center of the head, as shown in the drawings.

In Fig. 5 the soldering-iron and shank is it self divided into conductors D and E by having its corners made of insulating material I, the circuit being closed by the point of the head. The arrangement of the insulating material is illustrated inFig. 9.

Fig. 8 is a diagrammatic illustration of the solderingiron as applied to soldering a pipe, the current being derived from a secondary battery F, and is drawn to illustrate the use of the resistancecoil S, which I prefer to use IOO in one of the conductors E, as shown in the drawings, though it may be D, and which applies 'to all the figures, though only illustrated in Fig. 8.

When the conductors D and E are connected with the poles of a generator of electricity and a current is passed through them, the conductor Gr, being of comparatively high resistance, becomes heated, thereby heating the head A, which is used as an ordinary solderingiron. Vhen the reservoir-iron, as shown in Figs. 3 and 4, is used, the solder becomes heated and flows through the aperture O in the head. When the iron is constructed as shown in Fig. 5, the comparative difference of resistance of the different parts of the circuit varies less than With the construction in the other drawings, and a greater' heating-current is required to heat the iron.

The form of the conductor G may be very widely varied, it only being essential that that part of the circuit which is within the head A or soldering-iron proper and intended to give a heating effect, be of greater electrical resistance than the other parts of the circuit. Except when the reservoir-iron is used, the head A or soldering-iron proper may be filled with a non-conducting, heat-retaining, refractory material, such as clay, soapstone, &c.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. A soldering-iron having a hollow head, an electrical circuit extending into the head, and that part` within the head being of coin- Aparatively high resistance, a hole in the point of the head, and means for opening and closing said hole at will, substantially as shown and described.

2. A solderingiron consisting of a hollow head, a conductor of high resistance within said head and having its ends adapted to be connected with the poles of a generator of electricity, and a lining of refractory nonconducting material inclosing the circuit within the head, an opening at the point of the tool, and a valve for controlling said open# ing, whereby the interior of the ltool is adapted as a reservoir for melted solder, substantially as shown and described.

CHARLES L. COFFIN.

Witnesses:

CYRUs E. LoTHRoP, HENRY B. LoTHRoP. 

